1. Field of the Invention
The present invention relates to a jet propulsion unit for a watercraft, and more particularly to a reverse thrust deflector assembly.
2. Description of Related Art
Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries a rider and possibly one or two passengers. A relatively small hull of the personal watercraft commonly defines a riders' area above an engine compartment. An internal combustion engine frequently powers a jet propulsion unit which propels the watercraft. The engine lies within the engine compartment in front of a tunnel formed on the underside of the watercraft hull. The jet propulsion unit is located within the tunnel and is driven by an output shaft of the engine. In particular, an impeller shaft of the jet propulsion unit extends forward, through a wall of the hull tunnel, and is coupled to the engine output shaft. In this manner, the engine drives the jet propulsion unit.
The jet propulsion unit conventionally includes an impeller housing in which an impeller is contained. The impeller, which is driven by the engine through the impeller shaft, draws water through a water inlet and forces it through a discharge nozzle to propel the watercraft. A steering nozzle usually is mounted on the discharge nozzle for pivotal movement about a vertical axis. Pivotal movement of the steering nozzle about the vertical steering axis alters a discharge direction of the water jet to steer the watercraft.
Many personal watercraft also include a reverse thrust deflector to issue water forwardly and produce a reverse thrust. A pair of support arms typically support the reverse thrust deflector about the end of the jet propulsion unit. These arms usually are pivotally mounted onto the discharge nozzle or onto a ride plate that extends beneath at least a portion of the jet propulsion unit. The pivotal movement of the arms moves the reverse thrust deflector from a raised position, in which the deflector does not affect the water jet issuing from the steering nozzle, and a fully lowered position, in which the deflector cooperates with the steering nozzle and redirects water issuing from the jet propulsion unit forwardly to achieve a reverse thrust. In some prior watercraft, the reverse thrust deflector also assumes an intermediate position which corresponds to a neutral position.
Both the steering nozzle and the reverse thrust deflector are pivotally supported and are operated remotely. As such, each requires separate actuation mechanisms that must not interfere with each other. That is, the mechanism for actuating the reverse thrust deflector, which pivots about a horizontally disposed axis, must not interfere with the mechanism that affects the steering of the watercraft. For this reason, first and second flexible wire actuators usually are employed to operate the steering nozzle and the reverse thrust deflector, respectively. The layout of these components and actuators though typically is complicated owing to the tight confined area of the tunnel in which the components and actuators are disposed.
Prior the buckets are also prone to bouncing up and down when the watercraft is operated in reverse with the thrust bucket in the lowered position. The thrust bucket under some conditions or after repeated use may become worn and tend to rattle and move about when raised.